Adams Point alluvium

Adams Point isn’t really named Adams Point—the name refers to the neighborhood overlooking Lake Merritt from the north. (And it’s named for Edson Adams, who once owned it all.) But I like to think of the low peninsula of Lakeside Park, between the lake’s two arms, as being Adams Point proper. One day in early 2003 I strolled along the water at its base, looking for outcrops. It appears to be the only spot on the entire Oakland shoreline that is nearly in its original condition.

The rocks in this view are not original; they’re pieces of the old wall that lines the rest of the lake. And the large boulder is a decorative one that fell or was pushed down here from the park lawn up above. What truly belongs here is the sand and gravel, which makes up the lake shore and the hills around it, Haddon Hill on the east and Adams Point hill on the north. Both are part of a large alluvial fan of Pleistocene age.

Under the roots of a tree, I found the original sediments exposed:

This being a city park, I left the material untouched, but the pebbles of local red chert and bluish basalt are unmistakable. These particles eroded from the hills and were carried here by vigorous streamflow, which also rounded their sharp corners somewhat. Outside of building excavations, exposures of this material are rare in Oakland.

Wonderful information on our local almost-hidden geology! I’m leading a walking tour for Oakland Heritage Alliance tomorrow Sat. Aug. 9 at 10 a.m., and was happy to see your information on Adams Pt. geology. Yesterday at the public library history room, I was looking at maps showing the original course of Cemetery Creek (now called Glen Echo), which enters the lake at Harrison and Grand, coming down from cemetery area, the subject of your article on the old quarry over by Long’s. I will be passing along your URL to those who are interested, or if you aren’t doing anything more thrilling, meet us in front of the Lake Merritt Hotel at 10, and come along! It’s a leisurely walk and I am bringing copies of some old maps and historic photos of that part of the Lake.